PB2015: YOUNG ADULTS WITH MULTIPLE MYELOMA – A SINGLE CENTER EXPERIENCE
Authors: I. Dos Santos Marques, C. Sol, M. Henriques, P. Baptista, A. Airosa Pardal, P. Oliveira Monteiro, E. Aguiar, M. J. Soares, P. Gomes, R. Bergantim, F. Trigo
Journal: HemaSphere (2022)

Background: Multiple myeloma (MM) is a plasma-cell disorder characterized by clonal proliferation of malignant plasma cells in the bone marrow with monoclonal protein in the serum and/or urine, and associated organ dysfunction. It mainly affects the elderly population and is uncommon in younger than 40 years and extremely rare before 30 years. Since this is an incurable disease, it is important to understand its behavior in young adult patients for a better therapeutic decision and surveillance. Aims: Description of presenting features and outcomes of MM patients ≤45 years. Methods: Retrospective review of MM patients, aged ≤45 years followed up in a tertiary hospital, between 2008 and 2021. Data analysis was performed using the statistical program IBM SPSS Statistics 26®. The overall survival (OS) and progression-free survival (PFS) was estimated by the Kaplan‐Meier method. Results: It was included 28 patients [71,4% male (n=20), 28,6% female (n=8)], with a median age at diagnosis of 41 years (36-45). M-proteins consisted of IgG (n=12, 45%), IgA (n=9, 31,1%), light-chain (n=4, 14,3%) and non-secretory disease (n=1, 3,6%). According to the International Staging System (ISS), 35,7%, 35,7%, and 17,9% of the patients had stage I, II, and III disease at the time of diagnosis, respectively. The most common ‘CRAB’ symptom was bone disease (n=17, 60,4%), followed by anemia (n=10, 35,7%), hypercalcemia (n=5, 17,9%) and kidney failure (n=3, 10,7%); 12 patients (42,9%) had two or more ‘CRAB’ symptoms. Fluorescence in situ hybridization (FISH) was done in 57,1% patient specimens, and cytogenetic high-risk abnormalities [del(17p), t(4;14), t(14;16), t(14;20), gain 1q, or p53 mutation] were detected in 6 cases. Other chromosomal abnormalities, namely del(13q) and t(11;14) were found in 2 and 3 patients, respectively. Patients received induction treatment according local protocols [Vd (n=11), VTd (n10), CBd (n=3), VAd (n=2), TD (n=1), VTd-PACE (n=1)] followed by autologous stem cell transplant (ASCT). No patients had allogeneic stem cell transplant. Median follow-up time 68 months (7-165) with relapse was seen in 16 patients (57,1%) and the estimated median time until progression was 52 months. OS was not reached. Using univariate logistic regression analysis no association was found between overall survival or response to therapy, and disease staging, CRAB symptoms, cytogenetic abnormalities, immunophenotypic features or treatment strategy. Summary/Conclusion: Most data regarding the impact of age on survival mainly come from clinical trials developed before the current therapy choices were in use. However, some real-life studies evaluating young population of MM patients has been conducted to identify patient and disease features may have impact on this group of patients. The results of these studies are heterogeneous. On the other hand, in our population, ISS, CRAB symptoms, cytogenetic data, immunophenotypic features and treatment was not shown to have an impact on clinical course of the disease or survival. This study has limitations, particularly attributable to its retrospective nature, small number of patients within a single institution and lack of detailed information regarding imaging techniques, and comorbidities.